Defeat Caerina the Lost near the entrance and unlock the first Soulwell Teleporter ( 1, 0, 62 ) /waypoint 0.99, 0.20, 62.12, then clear the way to the Soulwell Tube ( 1, 16, -139 ) /waypoint 0.95, 16.24, -139.24

Enter and dive to the basement to unlock another soulwell. Follow Melanie Everling ( 4, -61, -101 ) /waypoint 4.33, -61.01, -100.95 through the 3 rooms wherein you'll be ambushed by bound manifestations. In the end kill her once she becomes aggro to free her ( -43, -60, -138 ) /waypoint -43.04, -59.87, -137.89.

Go back to the Soulwell Tube ( 1, -60, -139 ) /waypoint 0.95, -59.86, -139.24 and swim up past the first entrance to the next teleporter unlock in the Balistrade of Souls. Clear the area and kill the wandering Construct of Souls.

Go back to the Soulwell Tube ( 1, 62, -139 ) /waypoint 0.95, 62.40, -139.24 and swim up to the top of this tube by Bastion's Charge. Kill Bastion ( 1, 107, -224 ) /waypoint 1.00, 106.71, -224.00 to open the barrier blocking the way to Fitzpitzle's Rest. Kill Fitzpitzle ( -110, 110, -299 ) /waypoint -110.40, 110.08, -298.70 by following him through his 3 studies and beating him further each time.

Use the second Soulwell Tube ( 1, 109, -299 ) /waypoint 0.95, 108.69, -299.15 and swim up to the top floor to kill Oligar of the Dead.

Use the portal that spawns upon his death at ( 10, 19, 3 ) /waypoint 10, 19, 3 to go back down into the base of The Deathtoll Tower. Kill Drinal ( 1, 19, -23 ) /waypoint 0.91, 19.12, -22.86 who stands on the lift going all the way to the top of the Tower.

Note: Defeating Drinal before the lift has ascended will bug the lift out forcing you to call or evac out